There are many challenges presented in the agricultural industry with regards to maintaining the integrity of an agricultural product, such as an agricultural plant product. As one example, the presence of mold or yeast may cause spoilage or degradation of agricultural plant products, for example leafy vegetables and herbs, reducing shelf life and quality of the agricultural plant products. Further, certain agricultural plant products, such as cannabis, require a specific moisture content during processing.
Cannabis is a genus of a flowering plant (family: Cannabaceae) with three species: C. sativa, C. indica, and C. ruderalis, and several dozen strains. Cannabis is grown as a natural, organic, medicinal plant in green houses or outdoors, and growing cannabis involves a long drying process which may involve five or more days of the cannabis drying on the plant. In particular, current natural harvesting practices involve cutting grown cannabis plants, air-drying the whole plant for approximately five days at ambient temperature conditions to reach a moisture content of about 9%, as a moisture content of 9% is optimal for mechanical trimming (mechanical trimming requires approximately a 9% to 12% moisture content for effective leaf removal).
The flowering buds of the dried cannabis are then removed from the dried plant by hand, followed by mechanical trimming of the “sugar leaves” of the plants. The proper moisture content of the cannabis plants is important, as a cannabis product that is too dry may lead to buds that are too brittle and breaking apart, resulting in a lower quality product. On the other hand, if the moisture content is too high, the “sugar leaves” of the plant may not be mechanically removed.
During this drying process, changes in drying conditions (e.g., relative humidity, ambient temperature, seasonal weather, etc.) may result in varying moisture content of the product, causing longer drying times, and the development of yeast and mold growth may occur. Mold or yeast infections of cannabis in particular may lead to a significant reduction of usable crop for a grower, as in addition to spoilage issues, there are regulatory thresholds for an amount of mold or yeast that may be present in order to sell cannabis for medicinal purposes. For example, the state of Colorado requires cannabis sold to comply with a limit of less than 10,000 colony forming units per gram (CFU/g). The drying process for other agricultural plant products, such as leafy vegetables and herbs, may present similar challenges in regards to drying such agricultural plant products to a particular moisture content.
However, conventional approaches to controlling yeast and mold growth on agricultural plant products such as the use of heating, oxygen deprivation (e.g., with CO2), or use of other chemicals may not deliver acceptable results or quality of the agricultural plant products. For example, heating as a disinfecting strategy may be inconsistent, as it is difficult to ensure that all of the agricultural plant product reaches a killing temperature for the yeast and mold. Additionally, oxygen deprivation may not be a successful disinfection strategy, as yeast are anaerobic organisms. Lastly, application of other chemicals to agricultural plant products may require long processing times that range from hours to days, and these chemical applications to the agricultural plant products may not successively penetrate an agricultural plant product for sufficient reduction in killing of mold and yeast.
In view of the above challenges with conventional approaches to controlling yeast and mold growth on agricultural plant products, and recognizing that there is a need, for example, in the cannabis industry, to reduce yeast and mold on the dried product, the inventors herein have developed an alternative approach to controlling the presence of yeast and mold on agricultural plant products, such as leafy vegetables and herbs, and in at least some examples, cannabis. 
In one example, this alternative approach to processing agricultural plant products may include positioning agricultural plant products between two electrode assemblies of a radiofrequency (RF) circuit, closing the RF circuit, and heating the agricultural plant product to a threshold temperature in greater than a threshold amount of time. In at least one example, the agricultural plant product may be leafy vegetables. Additionally or alternatively, the agricultural plant product may be herbs. In at least one example, the agricultural plant product may be cannabis. 
This alternative approach to processing agricultural plant products may utilize RF heating as a post-harvest kill step to reduce the population of yeast and mold on the agricultural plant products. For example, the RF heating may be utilized as a post-harvest kill step to reduce the population of yeast and mold on dried organic cannabis or other agricultural plant products with minimal negative impact on the chemical composition (e.g., THC content, terpenes), natural, and organoleptic composition of the product. For example, the minimal negative impact on the chemical composition may include a minimal negative impact on color, aroma, and flavor chemicals of the agricultural plant products.
This alternative approach may be used to quickly dry the agricultural plant product for improved downstream processing. Thus, RF heating may be beneficial for removing moisture quickly to shorten the drying process, reduce the time available for yeast and molds to grow, reduce the water activity, improve handling and mechanical processing, and effectively reduce the microbial load of the product. Moreover, specifically in a case with cannabis, the use of RF heating may achieve drying and microbial reduction benefits without a significant impact on the medicinal properties of the cannabis. 
Further, by utilizing RF to heat the agricultural plant product, several advantages over traditional approaches to disinfecting agricultural plant products may be achieved. For example, RF heating may be energy efficient compared to other heating methods such as natural gas based systems, steam jacket systems, or electrical heating, as RF based heating penetrates the agricultural plant product, increasing a vibration of polar molecules within the product to heat it, as opposed to heating a product via conduction. Additionally, RF may be more efficient than oxygen deprivation and chemical application for killing yeast and mold. Furthermore, by heating the agricultural plant product to a threshold temperature in greater than a threshold amount of time, the technical effect of a uniform temperature throughout the RF heated agricultural plant product and drying of the product may be achieved due to both steam caused by the RF heating and the RF waves themselves being able to penetrate the agricultural plant product.